In the days of film, certain formulas were known to enhance different parts of the color spectrum over others. Generally Fuji film emphasized Green hues and Kodak emphasized Red hues.
The iPhone camera seems to emphasize Red hues in the color spectrum. The light receptor seems to really boost colors in the Red range.
The Red accent light on this staircase is boosted into a Red glow that contrasts sharply with the blackness around it. The room itself wasn’t nearly as dark, but the slow shutter speed of the camera emphasizes the Red over all other hues and the remainder appears black as a result.
The Red leaves of this Japanese Maple were a Burgundy to Brick Red under the ambient light of a grey, autumn afternoon, but the iPhone camera’s receptors push them into the Magenta to Crimson range, while leaving the yellow leaf unaffected.A pretty Red cactus bloom in the morning sun. The Red hues are boosted to an almost glowing degree while the greens, browns and yellows of the surrounding plants and stones are much more natural.